Where does it say 540? On the drive's label?
What else does it say on the label? (Brand, model, etc).

On Fri, 28 May 2004 18:31:33 -0700, "Jeno1"

That's an odd limit - "504M" is the more common one, so it doesn't
look like a straight BIOS addressing limitation.

Was this HD set up on the PC that's currently trying to read it?

I ask, because PCs of that generation evolved through different
addressing strategies, and a mismatch can give you this mileage.  

Generally, the trend has been away from Cylinder, Head, Sector (CHS)
addressing towards Logical Block Addressing (LBA) that uses linear
physical sector addresses, leaving CHS mechanics to the HD itself.  

So BIOS/CMOS setup will typically offer Normal (CHS), Large and LBA
addressing modes.  Large is used by some UNIX and balances the
notional head and cylinder counts differently to LBA.

If you use the wrong addressing mode, you may not see the hard drive's
partitions.  Some partitioning conventions still care about CHS
alignment - so even though in theory, as long as the total number of
sectors matches that of the physical HD it should work, in practice
the wrong CHS values can cause partitions to vanish, etc.

Also, within the evolution of LBA, the way the notional CHS values
were derived has changed from a variable number of heads to 255 heads
in all cases.  With this change has come an increase in granularity,
e.g. whereas before you might have been able to set partition or
volume sizes to 511M or 1023M, nowdays this is rounded to the nearest
8M so you have to settle for 509M and 1019M.

It sounds to me that going for "270M" is choosing a head count that
matches what was used when the HD was originally set up, so that the
primary partition's boot record appears on CHS 0,1,1 as expected.  But
you may find this fails when you try to access the rest of the volume;
for example, Scandisk may complain it is unable to access the last
sector of the hard drive volume.

This is potentially dangerous stuff; you could lose data or corrupt
the contents of your partitions if you get these settings wrong.  Can
you give more detail on the history, e.g. where was this HD set up,
what were the specs of the PCs involved, etc.?

  I'm baaaack!

What model of hard drive is it?